
/***************************************************************************
 *   Copyright 2006-2009 by Christian Ihle                                 *
 *   kontakt@usikkert.net                                                  *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/

package net.usikkert.kouchat.util;

import java.net.URL;

import java.util.HashMap;
import java.util.Map;

/**
 * This class validates if any resources are missing.
 *
 * @author Christian Ihle
 */
public class ResourceValidator
{
	/** The map of resources to validate. */
	private final Map<String, URL> resourceMap;

	/**
	 * Constructor.
	 */
	public ResourceValidator()
	{
		resourceMap = new HashMap<String, URL>();
	}

	/**
	 * Clears all the added resources from the validation list.
	 */
	public void clearResources()
	{
		resourceMap.clear();
	}

	/**
	 * Adds a resource to be validated.
	 *
	 * @param resource The resource to check.
	 * @param location The location of the resource.
	 */
	public void addResource( final URL resource, final String location )
	{
		resourceMap.put( location, resource );
	}

	/**
	 * Checks if any of the resources were not loaded, and returns a
	 * string with a list of the locations of the missing resources.
	 * Each location is on a separate line.
	 *
	 * @return A list of the resources that has not been loaded.
	 */
	public String validate()
	{
		StringBuilder missingResourceList = new StringBuilder();

		for ( String location : resourceMap.keySet() )
		{
			if ( resourceMap.get( location ) == null )
			{
				if ( missingResourceList.length() != 0 )
					missingResourceList.append( "\n" );

				missingResourceList.append( location );
			}
		}

		return missingResourceList.toString();
	}
}
